1. Field
The present disclosure relates to a fuel-cell vehicle.
2. Description of the Related Art
Fuel-cell vehicles include a fuel cell system that serves as a power supply system of the fuel-cell vehicle. A fuel cell generates electricity when receiving hydrogen gas serving as fuel gas and air serving as oxidant gas. The fuel-cell vehicles further include a hydrogen tank that stores hydrogen gas to be used by the fuel cell to generate electricity. Users fill the vehicles with hydrogen gas required for generating electric power at a hydrogen filling station.
In recent years, research and development on filling a hydrogen tank with hydrogen gas have become increasingly popular. For example, Japanese Unexamined Patent Application Publication No. 2011-33068 describes the following technique. That is, when a hydrogen filling device installed at a hydrogen filling station is connected to a fuel-cell vehicle to fill the hydrogen tank with hydrogen gas, the vehicle sends a data signal indicating the temperature and the pressure of the hydrogen tank to the station. The station monitors the state of the hydrogen tank (e.g., the hydrogen density) that is being filled with hydrogen gas on the basis of the data signal received from the vehicle and detection signals of sensors mounted in the station. Thus, the station completes supplying the hydrogen gas at an appropriate timing so that the tank is filled up. As used herein, such a technique for supplying hydrogen gas to fill the tank while performing communication is referred to as “communication filling”. In addition, a technique for supplying hydrogen gas to fill the tank without performing communication is referred to as “non-communication filling”.
As described in Japanese Unexamined Patent Application Publication No. 2001-351667, in general, existing fuel-cell vehicles do not allow the users to charge hydrogen gas into vehicles with the fuel cell system running (i.e., during the hydrogen gas in the hydrogen tank being consumed). However, in some cases, when the vehicle is being charged with the hydrogen gas and if the user powers on an air conditioner of the vehicle, the fuel cell system is started and, thus, the charging operation is stopped. Accordingly, in recent years, a demand for charging hydrogen gas into a vehicle even when the fuel cell system is running has been on the rise.